Do you remember in the past we were warned to be careful about being in debt because interest never stopped charging us, interest never slept, never took a day off, never took a holiday. Well the reverse is true, as well.

Is your money making money while you sleep? Does it sound too good to be true? Since we still live in the age of the internet, it’s not that difficult to earn extra money on the side.

With that in mind, here are 11 ways that you can actually earn money while you sleep.

1. Start a blog.

Perhaps the most popular way to earn a passive income is by launching your own blog. It only takes a couple of minutes to set up and is cheap to start – just purchase your domain name and pay for hosting.

After that, start creating amazing content that people would be interested in reading or sharing. For example, if you’re an accountant that has helped small business owners with their taxes, then that could be your blog. I personally have my invoicing blog to help customers know everything there is to know about invoicing. This draws thousands of signups a month.

Make sure the topics you write about are popular. If you still love your pet rock, I doubt there would be enough people visiting your our site to monetize it. But, you never know.

Once you’ve gained a following, you can start making money from of your blog by:

Earning commissions as an affiliate. This is where you push other people’s products or services on your site. Make sure these products or services are relevant to your blog. For example, that accounting blog could become an affiliate for accounting or invoicing software. Once you find an affiliate partner you’ll be given a unique code so that whenever a visitor clicks that link on your site you’ll earn your commission.

Sell-advertising. If you’re site has the traffic to become an affiliate, then it may also be good enough for advertisers to purchase ads on your site. You may start off small, like making under $20 per ad. But, you may eventually be able to charge triple digits. Again, you site must be quality.

Find sponsors. This is slightly different from just selling ads on your site. Sponsorships may be a one-off piece of sponsored content or permanent logo embedded in your footer.

2. Sell your own information product.

If you’re knowledgeable in a certain area, then you can start creating products, such as eBooks or videos, and selling them on your blog. It may take a lot of work to create and market your products, but once all the leg work is over, you can just set back and collect the proceeds.

Related: 7 Speedy Business Tips From NASCAR Driver Dale Earnhardt Jr.

3. Earn royalties.

If you’re a talented musician, actor, or author, then you could earn royalties from your work. In other words people will pay you for using your work or creative assets.

If you aren’t talented enough, but still interested in earning royalties, then check out Royalty Exchange. It’s a marketplace where you can buy and sell royalties.

4. Create a membership community.

If you’ve proven yourself to be a authority figure, then you can create a membership community where you pay a monthly fee to receive additional high-quality content and information that’s not available to non-members.

One of my favorite examples is Timothy Sykes who makes more than $100,000 per month in passive income through his membership community which discusses how people can make money in trading penny stocks.

5. Install an autoresponder.

Another common online business model is using autoresponders to sell services, products or memberships. This is where people leave their email address on your site and then they’ll receive an automated email containing the link to download products or quality information you have to offer, as well as follow-up with a series of emails.

You’ll a need service like OptinMonster to make this possible. I also recommend you read this Quick Sprout guide to get started with autoresponders.

6. Flip websites.

If you’ve put in the time and effort in building a website and you have gained a lot of traffic, then you may be able to sell it to an interested party by listing on marketplaces like Flippa. I’ve bought and sold a lot of sites here and made a lot of money.

7. Sell physical products.

Just like with a blogging site, there are several ways to earn a passive income by selling physical products. Probably one of the best known ways is by selling your old junk on eBay. But even if you don’t have anything left to sell you can start drop shopping. This is where you sell products for a company on eBay or Amazon and they’ll take care of the rest — including shipping.

You can also launch your own eCommerce store by using Shopify. They literally give you everything you need to sell products online from a complete online shop to including buy buttons on your social media channels.

Related: 7 Ways to Make Extra Income Even With a Full-Time Job

8. Invest in stocks or shares.

When you invest in stocks you become a stakeholder. That entitles you to a share of their profits. Investing in stocks has been a popular way to earn a passive income for years, and thanks to the internet, it’s easier than ever to research and invest in stocks on your own.

Keep in mind that the stocks you invest in can change throughout the various stages of life. For example, I look for investments that can benefit my daughter, such as a CA529 plan that will go towards her college tuition.

9. Peer-to-peer lending.

Companies like LendingClub, Propser, and Harmoney have created a new industry where anyone can become a lender. They will then match you with a consumer who either prefers or has trouble securing a loan from a bank. You can earn a higher interest rates on the loans you issued since you’re dealing directly with the borrower.

10. Rent out property.

Thanks to Airbnb, you can rent out your home while on vacation or your vacation home when not in use. You can also rent out your garage, parking space, or unused office space. It’s a nice supplemental income without really doing anything except placing an ad.

11. Hire a middleman.

This is also known as arbitrage and is basically where you have someone else do the work for you. For example, you could start a dog walking service or web design firm, but outsource the actual dog walking or coding to someone else. You’re much better doing anything except being the middleman who is in charge of marketing these services.